1. Field of the Invention
The present invention relates to a device and method for inputting and outputting data to and from a device such as a mobile phone terminal including an interface for a semiconductor memory, and others.
2. Description of the Related Art
Mobile phone terminals have recently been equipped with a high-definition digital camera, a digital audio player for reproducing high-quality music and others. Besides, the number of addresses that can be registered in an address book (a phone book) of mobile phone terminals increases dramatically. Along with such evolution, data having a size larger than ever before is handled in mobile phone terminals.
Further, mobile phone terminals have been equipped with an interface for coupling a large capacity semiconductor memory. In addition, the capacity of an internal memory has been increased. This allows a backup of a large amount of data in a semiconductor memory, for example, image data of an image photographed by a digital camera of a mobile phone terminal, image data sent from other mobile phone terminal, data in an address book or music data.
Thus, since functions of mobile phone terminals are improving day by day, many users replace mobile phone terminals with new ones once in a few years. On this occasion, if an old mobile phone terminal has data to be used continuously in a new mobile phone terminal, it is necessary to transfer such data from the old mobile phone terminal to the new mobile phone terminal.
In regard to this matter, putting a method described in Japanese unexamined patent publication No. 2002-359694 to practical use is possible. According to the method, a mobile phone terminal and a personal computer are connected to each other via a USB cable. Then, data stored in the mobile phone terminal can be outputted to the personal computer and be saved therein. This method is applied as follows: An old mobile phone terminal and a personal computer are connected to each other and data stored in the old mobile phone terminal is transferred to the personal computer once. Then, a new mobile phone terminal and the personal computer are connected to each other and the data that has been backed up is transferred to the new mobile phone terminal. In this way, data transfer can be performed from the old mobile phone terminal to the new mobile phone terminal.
The version of USB that is used for connection to a mobile phone terminal is version 1.1. Accordingly, in the method described in Japanese unexamined patent publication No. 2002-359694, a mobile phone terminal transfers data at a rate of approximately 1.5 Mbps (bit per second). However, since large size data is handled nowadays, in some cases, it may take much time to transfer data at this rate.
The USB 1.1 has a full-speed mode, i.e., a mode for transferring data at a rate of 12 Mbps. This mode, however, lacks stability compared to a low speed mode (a mode at a rate of 1.5 Mbps). Accordingly, in order to use the full-speed mode, error-handling logic such as retransmission control is necessary. It is difficult, however, to use the full-speed mode in mobile phone terminals on which strict conditions are imposed such as a small casing, a low cost and electric power saving. In short, it is desired that mobile phone terminals can achieve data transfer at a higher rate than ever before with the current specifications maintained as much as possible.